1. Field of the Invention
The present invention relates to a cutting machine comprising:
a cutting mechanism extending: PA1 in the work position, transversely to the direction of travel and level with the ground; PA1 in the windrowing position, transversely to the direction of travel and at a certain distance above the ground; and PA1 in the transport position, substantially vertically upwardly oriented; PA1 a hitching structure intended to be connected to the hitching device of a motor vehicle; PA1 a carrying beam connected on the one hand to the hitching structure by means of a first articulation and on the other hand to the cutting mechanism by means of a second articulation; PA1 an operating device allowing the cutting mechanism to be brought into the various positions and comprising: PA1 an operating member comprising a latch intended to stop the upwards pivoting of the cutting mechanism about the longitudinal axis of the second articulation during movement into the windrowing position; and PA1 an operating ram connected at one of its ends to the operating member and at the other of its ends to the hitching structure by means of two corresponding articulations. PA1 the retractable stop limits the travel of the operating ram when the cutting mechanism is extending in the windrowing position, which advantageously allows the surplus energy developed by the operating ram compared with the energy needed to keep the cutting mechanism in the windrowing position to be transferred to the retractable stop; PA1 the retractable stop is connected to the operating ram by means of an articulation that is at least substantially parallel to the articulations that connect the operating ram to the operating member and to the hitching structure, which allows the retractable stop to be pivoted into an inactive position; PA1 the retractable stop is connected to the rod of the operating ram by means of the articulation at least substantially parallel to the articulations that connect the operating ram to the operating member and to the hitching structure; PA1 the retractable stop is intended to rest against the body of the operating ram in the windrowing position; PA1 in the windrowing position, when the retractable stop is resting against the body of the operating ram, the line of action of the retractable stop is at least substantially coincident with the longitudinal axis of the operating ram, which allows the operating ram to work in good conditions without it being subjected to high bending stresses; PA1 in the work position and in the windrowing position, the retractable stop rests on the rod of the operating ram via a protective member intended to protect the rod; PA1 the protective member is made of flexible plastic and is fixed to the retractable stop; PA1 the control mechanism that allows the retractable stop to be set in place and to be retracted comprises a cam which acts on the retractable stop when the cutting mechanism is brought from the work position or from the windrowing position into the transport position; PA1 the cam acts on the retractable stop so as to make it pivot about the articulation that connects the retractable stop to the operating ram; PA1 the cam forms part of a lever belonging to the operating member, the lever being articulated at one of its ends to the end of the operating ram and at the other end to the carrying beam or to the cutting mechanism; PA1 the cam is fitted to the lever belonging to the operating member in such a way that a certain angular variation between the said lever and the operating ram as the cutting mechanism is being placed in the transport position, makes the cam act on the retractable latch in such a way as to make it pivot about the articulation that connects the retractable stop to the operating ram; PA1 the cam acts on the retractable latch when the value of the angle between the lever and the operating ram increases; PA1 the latch of the operating member can be retracted to allow the cutting mechanism to pivot upwards about the longitudinal axis of the second articulation with a view to placing it in the transport position, thus making it possible to increase the value of the angle between the lever and the operating ram, this having the effect of retracting the retractable latch to bring to an end the phase of placing the cutting mechanism in the transport position.
2. Discussion of the Background
A cutting machine of this kind is known from document FR 96 05051.
This cutting machine broadly speaking comprises a cutting mechanism, a hitching structure, a carrying beam and an operating device.
The carrying beam is connected on the one hand to the hitching structure by means of a first articulation and on the other hand to the cutting mechanism by means of a second articulation.
The operating device comprises an operating member comprising a first lever connected to the cutting mechanism, a second lever connected to the carrying beam and to the first lever, and a latch intended to stop the upwards pivoting of the cutting mechanism during movement into the windrowing position.
The latch is composed of a third lever connected on the one hand to the second lever and on the other hand coming to rest against the carrying beam while the cutting mechanism is being placed in the windrowing position.
The operating device additionally comprises an operating ram which in particular allows the cutting mechanism to be brought into the windrowing position. This operating ram is connected to the hitching structure and to the second lever.
The assembly composed of the operating ram, the hitching structure, the carrying beam and the second lever forms a deformable quadrilateral.
When the operator wishes to move the mower from the work position to the windrowing position, he actuates the operating ram, from the motor vehicle, and this ram shortens causing the cutting mechanism to pivot upwards about the second articulation until the latch comes to rest on a stop provided on the carrying beam. From that moment on, the cutting mechanism and the carrying beam pivot about the first articulation that connects the carrying beam to the hitching structure until a limiting device fitted between the hitching structure and the carrying beam limits this second pivoting.
The energy developed by the operating ram depends on the power of the motor vehicle by means of which it is operated. In the windrowing position, all of the energy developed by the operating ram is transferred to the hitching structure, the operating member and the carrying beam, and this means a hitching structure, an operating member and a carrying beam, together with the various articulations concerned, which are particularly highly stressed.